A recent Windows 11 update quietly tanked gaming performance, triggering major frame rate drops in several titles most notably Assassin’s Creed Shadows. Benchmarks from Digital Foundry reveal the issue wasn’t minor: frame rates dropped by over 50% in some scenes.

While Nvidia eventually issued a hotfix, gamers are left wondering how such a massive slip made it past Microsoft’s QA.

Update triggers huge performance loss

The problem began after the KB5066835 patch rolled out for Windows 11 versions 24H2 and 25H2. Users started noticing stuttering, frame pacing issues, and sudden FPS dips.

Digital Foundry ran detailed tests using a Ryzen 7 9800X3D and RTX 5090, showing a drop from 72 fps to 34 fps in Assassin’s Creed Shadows at 4K with DLSS enabled until Nvidia’s 581.94 hotfix reversed the damage.

Nvidia hotfix cleaned up the mess

Nvidia released a driver update on November 19th addressing the sudden drop in performance. In their patch notes, they admitted that “lower performance may be observed in some games after updating to Windows 11 October 2025 KB5066835.”

This fix came just in time for many players, but the question remains: Why was this Nvidia’s mess to clean up?

Windows 11 update fallout sparks harsh criticism

The Digital Foundry team didn’t hold back. Alex Battaglia called Microsoft an “absolutely terrible steward for their operating system.” He and others argued that the company is now too dependent on hardware partners like Nvidia to keep gaming performance stable.

Their concerns boil down to three key points:

• Lack of communication between Microsoft and GPU vendors
• Possible DirectX compatibility issues post-patch
• Poor visibility on how Windows updates impact gaming

The team stressed that AI innovation is being prioritized over core PC gaming performance, at a cost.

Windows 11 update problems extend beyond frame rates

Performance drops aren’t the only concern. Microsoft’s recent UI changes under the “Full Screen Experience” banner have landed on handhelds and will soon hit desktop builds. Unfortunately, the reported frame rate improvements are minimal, and the update introduces new bugs.

For PC gamers, this isn’t just frustrating, it’s disruptive.

SteamOS looks more appealing as Windows 11 stumbles

While Valve’s Steam Machine is still in development, the chaos caused by the Windows 11 update makes alternatives more attractive. With growing interest in Linux-based gaming and tools like Bazzite gaining traction, Microsoft’s grip on the gaming PC experience might be loosening.

At the very least, gamers are watching closely and backing up their drivers.